Charles O. Perry disclosed Rhombic Hexahedra Blocks for making Rhombic Dodecahedra in his U.S. Pat. No. 3,611,620, in which geometric toy blocks can be made by fitting four obtuse hexahedra together to have geometric shapes, and however have the following defects:
1. Even many shapes of geometric polyhedra can be assembled by assembling several individual polyhedron units different from each other. The production cost for modling the basic units such as cubical hexahedron, rhombic hexahedron or other shapes will be increased.
2. Every two neighboring blocks are coupled by pair of stems and spherical end portions. The stems as fixed inside each block may increase their production complexity and each stem may be broken or damaged after repeated services.
3. It is difficult to assembly an irregularly shaped toy bokcs such as to mimic an animal, a machine or an article since they are lacking of linear linking elements or rotating elements, so that it is difficult to form diversified vivid gigantic structures.
The present invention has found the defects of such a conventional blocks and invented the present block unit for making three dimensional blocks.